Vermes
Advanced Member level 4
This is a construction of car active subwoofer – Rockford + Holton. It consists of a converter on ETD44 and amplifier Holton 200 with a place for third pair of MOSFETs.
Speaker and housing:
Speaker: Rockford Fosgate R1S412. Housing has a capacity of 34 liters, without the milling for the speaker, covered with gray carpet.
Converter and amplifier:
Converter without stabilization is based on sg3525, frequency of about 45kHz. Transformer on core ETD44 was mounted on a wire cover. Horizontal carcass, 2x4/22 wires 0,5mm - primary winding, 2x18/5 wires 0,5mm – secondary winding. Outputs are ended with connectors to facilitate possible disassembly. The device uses keys 2x IRFZ44n. Schottky are four parallel MBR20100CT.
Amplifier Holton 200. LM385-1,2 for stabilized quiescent current. There are no filtering capacitors 4700uF 63V in the pictures. All greater semiconductors are on the heat sink A6023.
Supply is switched from remote signal by 30A relay, it takes 130mA. Sockets for supply, signal and remote cables were made using previously disassembled socket from an old housing. Signal chinches were put in the holes. Remote connector is simple 3mm female connector. One hole was sealed using the connector and the other by thermo-glue.
Firstly sides were covered with veneer, then one big piece from the bottom, through front and to the back.
Pictures:
Soldering 16mm^2 cable:
Angle:
Link to original thread - Subwoofer aktywny Rockford + Holton